Is this reminiscent of post 9/11 with the Anthrax scare? Is it possible the multiple bombings and ricin are the work of one group?

An envelope containing ricin was sent to the Capitol Hill office of Sen. Roger Wicker, lawmakers told Fox News on Tuesday.

Milt Leitenberg, a University of Maryland bio-terrorism expert, said ricin is a poison derived from the same bean that makes castor oil. According to a Homeland Security Department handbook, ricin is deadliest when inhaled. It is not contagious, but there is no antidote.

The letter to the Mississippi Republican was intercepted at an off-site mail screening facility and never reached the Hill.

Wicker thanked law enforcement officials in a statement for “their hard work and diligence in keeping” those who work in the Capitol safe, adding that the matter is part of an ongoing investigation by Capitol Police and the FBI. “Gayle and I appreciate everyone’s thoughts and prayers,” he said.

As of Tuesday night, mail delivery had only been stopped to the Senate, not the House. Fox News

What ricin is

Ricin is a poison found naturally in castor beans. If castor beans are chewed and swallowed, the released ricin can cause injury. Ricin can be made from the waste material left over from processing castor beans.

It can be in the form of a powder, a mist, or a pellet, or it can be dissolved in water or weak acid.

It is a stable substance under normal conditions, but can be inactivated by heat above 80 degrees centigrade (176 degrees Fahrenheit).

Where ricin is found and how it is used

Castor beans are processed throughout the world to make castor oil. Ricin is part of the waste “mash” produced when castor oil is made.

Ricin has been used experimentally in medicine to kill cancer cells.

How you could be exposed to ricin

It would take a deliberate act to make ricin and use it to poison people. Unintentional exposure to ricin is highly unlikely, except through the ingestion of castor beans.

If made into a partially purified material or refined into a terrorist or warfare agent, ricin could be used to expose people through the air, food, or water.

In 1978, Georgi Markov, a Bulgarian writer and journalist who was living in London, died after he was attacked by a man with an umbrella. The umbrella had been rigged to inject a poison ricin pellet under Markov’s skin.

In the 1940s the U.S. military experimented with using ricin as a possible warfare agent. In some reports ricin has possibly been used as a warfare agent in the 1980s in Iraq and more recently by terrorist organizations.

Ricin poisoning is not contagious. Ricin-associated illness cannot be spread from person to person through casual contact. However, if you come into contact with someone who has ricin on their body or clothes, you could become exposed to it.

How ricin works

Ricin works by getting inside the cells of a person’s body and preventing the cells from making the proteins they need. Without the proteins, cells die. Eventually this is harmful to the whole body, and death may occur.

Homeland Security Secretary Janet Napolitano: Bombings Not Part of a Broader Plot.

Homeland Security Secretary Janet Napolitano said Tuesday that there was “no current indication” that the Boston Marathon bombings were part of a broader plot, but declared that her agency would keep “enhanced security measures” in place at transportation hubs just in case.

Napolitano’s statement came after she took part in an Oval Office meeting with President Barack Obama and top national security aides to discuss the investigation of, and response to, the attacks.

“While there is no current indication to suggest that the events in Boston are indicative of a broader plot, out of an abundance of caution, DHS continues to keep in place enhanced security measures at transportation hubs, utilizing measures both seen and unseen,” Napolitano said.

“We continue to urge the American public to remain vigilant and immediately report any signs of suspicious activity to local law enforcement officials,” she said.

President Barack Obama discusses the Boston bombings with top national security aides (Pete Souza/Official White House

Bomb Details Emerge – Pressure Cookers Designed to Mame

The pressure cookers were filled with nails, ball bearings and black powder, and the devices were triggered by “kitchen-type” egg timers, one official said.

The resulting explosions sent metal tearing through skin and muscle, destroying the lower limbs of some victims who had only shreds of tissue holding parts of their legs together when they arrived at the emergency room of Massachusetts General Hospital, doctors there said.

Law enforcement officials said the devices were probably hidden inside dark nylon duffel bags or backpacks and left on the street or sidewalk near the finish line. Forensic experts said the design and components of the homemade devices were generic but that the marking “6L,” indicating a six-liter container, could help identify a brand and manufacturer and possibly lead to information on a purchase.

New details about the explosives emerged as President Obama announced that the F.B.I. was investigating the attack as “an act of terrorism,” and made plans to come to Boston on Thursday for an interfaith service at the Cathedral of the Holy Cross.

But officials said they still had no suspects in custody and did not give the impression that they were close to making an arrest as they repeatedly noted that the investigation was in its infancy.

Later in the article:

The scale of the attack and the crude nature of the explosives, coupled with the lack of anyone claiming to have been the perpetrator, suggested to experts that the attacker could be an individual or a small group rather than an established terrorist organization.

“This could have been a one-person job,” said Bruce Hoffman, a terrorism specialist at Georgetown University. “That makes it much harder to track. When we catch terrorists, it’s usually because they’re part of a conspiracy and they’re communicating with one another.”

Nonetheless, a senior law enforcement official said that authorities were also looking into connections between pressure cookers and Al Qaeda in the Arabian Peninsula, the Qaeda franchise in Yemen, largely because the design of the explosive device was described in a 2010 issue of the group’s online English magazine, “Inspire.”

“The pressurized cooker is the most effective method,” the article said. “Glue the shrapnel to the inside of the pressurized cooker.” The article was titled “Make a Bomb in the Kitchen of Your Mom.”

Pressure cookers are designed to contain high pressure in order to cook food faster. Pressure cooker bombs work when explosive powder is set off inside the pot, and the resulting pressure builds until it exceeds the ability of the pot to contain it, creating a blast of tremendous force. Rudimentary explosive devices made from pressure cookers have been widely used in attacks in Afghanistan, India, Nepal and Pakistan, all countries where the cooking device is common, according to a Department of Homeland Security warning notice issued in 2010.

But they have occasionally turned up in attacks in the United States as well: Faisal Shahzad, an American citizen who attempted a car-bomb attack on Times Square in May 2010, included a pressure cooker loaded with 120 firecrackers in the collective of improvised explosives in his S.U.V. The devices smoked but never exploded.

Instructions for assembling them can be found in many places on the Web, including in terrorism “cookbooks” popular among domestic extremists, and the Qaeda magazine is easily available on the Internet. So the design did not necessarily point to a foreign connection.

A law enforcement official said that the pressure cooker in Boston “was badly damaged,” adding, “you can barely tell what it was.” But enough of it remained intact to identify it, the official said. New York Times

Some Photos Are Graphic in Nature…Viewer Advised:

Hundreds gather for vigil on Boston Common to sing hymns, light candles following bombings

BOSTON — Hundreds of people gathered for a vigil on the Boston Common sang songs and lit candles one day after the bombing attack on the city’s marathon.

Several hundred people turned out Tuesday evening with banners declaring “Peace here and everywhere” and “Boston, you’re our home.”